You can use the user.create or the user.registration.create webhook to do something like this.

If you enable these webhooks and configure the transaction to require the webhook to succeed, then you simply need to return a non-200 status code from the webhook to cause FusionAuth to fail this create.

https://fusionauth.io/docs/v1/tech/events-webhooks/#tenant-settings
https://fusionauth.io/docs/v1/tech/events-webhooks/events/#user-create
https://fusionauth.io/docs/v1/tech/events-webhooks/events/#user-registration-create

@eirikur That is awesome, thanks so much for sharing your settings.

We handle all of this and you can use the native UIs for each of these when on mobile. This is all handled automatically by Facebook, Google, Apple and others.

More about external login providers.

@dan no problem at all. Completely understand it's tough offering support without reviewing how we have things setup.

Appreciate you shooting that link over and will do some investigation on our end to see what might work best for us.

Thanks!